Maker Pro
Maker Pro

Have been given a disassembled Whirlpool grill-microwave oven with missing decals & fuses?

Benny7440

Jan 14, 2016
88
Joined
Jan 14, 2016
Messages
88
Very good post, debe, thanks!

My readings with everything isolated are as follows:
Power xFormer's Primary = 0.6 ohms & to gnd ~= infinite;
Power xFormer's Secondary 0.2--->0.3 ohms & to gnd ~= infinite;
Isolated-electrode from xFormer to Diode resistance to gnd = 115 ohms;
Magnetron (electrode to electrode) ~= 0.3 ohms & to gnd ~= 29.1 ohms;
Condenser (electrode to electrode) it starts going down from ~16 Mohms in both polarities & from each electrode to gnd (both polarities) ~= infinity;
Power Diode exhibit a resistance of infinity at both polarities.

From the above measurements, do it seems there's a problem with one of the components? Thanks in advanced for any hint!
 

debe

Oct 15, 2011
278
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Oct 15, 2011
Messages
278
29.1 Ohm to ground on the Magnetron indicates a short. Magnetron is faulty. The reading should be Infinity.
 

Benny7440

Jan 14, 2016
88
Joined
Jan 14, 2016
Messages
88
I've changed the magnetron & everything is now well. Thanks to all that replied with your comments, you really helped me understand this appliance!

I still have a question, how come a magnetron gets to have such a reading, is it for rough handling, pollutants in the atmosphere (salty due to beach proximity) or a manufacturing deviation from quality standards?
 

debe

Oct 15, 2011
278
Joined
Oct 15, 2011
Messages
278
It just happens they either develop a short or they just stop working. Also microwave ovens do not like operating with no load in them or metal objects this shortens the life of the magnetron. Also poor ventilation (seen them built in to cuboards) & over heat & wreck the magnetron,
 
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